Pump



July 26, 1949. w. ERNST ETAL 2,477,444

PUMP

Filed Aug. .30, 1946 2 Sheets-Sheet 1 INVENTbRS WARREN R.T.U ER WALTER ERN BY jcillmm gmllm ATTORNEYS July 26, 1949. w. ERNST ETAL 2,477,444

PUMP v Filed Aug. so, 194s 2 Sheets-Sheet 2 FIG. 2

mvnn'ons WARREN R. TUCKER WA LTE R E R N ST BY gwzmim ATTORNEYS Pate nted July 26,

PATENT OFFICE p rom fWalter Ernst, Mundane, and wan-en n.

"TuckerJDayton, Ohio, assignors to HP-'M De- L velopmentCorporatiom; W gton, Del., a corporation ofDelaware l I "Application gust so; 1946, saw N6. 694,030

9Claims.w(0l. 103-37) 'I'lusinvention relates to fluid operable appa- Figure 3 is a plan section through the pump ratus and particularly to pumps. kMore partic indicated bythe line 3-3 on Figure l; ularly still, thisinventionrelatesto'duplexpumps Figure 4! is a view of the pump of-Figures 1 adapted to [pumping fluidfselejctively at one or through 3 in the act of displacing fluid to the another-pressure. p 5 discharge conduit; and

In many instances in connection with hydraulic Figure 5 is asectional view through a modified equipment itis desirable tohave a hand pump form of the pump. 9 l A availableeither as the principalsourceiof pres- Referring to the drawings, there is'shown in sure eras s; auxiliaryorfstand-by pressure Figure 1 the pumping 'mechanism according to sourceil Instanceswherein hand pumpscomprise 110 this inventionwhich is generally indicated at m necessary auxiliary equipment are, laboratory andwhichhas a discharge conduit l2 leading to type presses and otheflaboratory equipment, airthe inlet port of a fluid motor 14. The said port craft hydraulic circuits for: actuating landing is aisoconnected through a shut-off valve l6 and gearsQ-iiaps, etc, andsirnilar circumstances a conduit l8 withthe pump II) to return fluid wherein the serviceofthe pumpisintermittent lfithereto. t orlight. j Referring to Figures 1, 2 and 3together, itwill One or the difliculties hretofore encountered be seen that the pump comprises a'fluid reset with hand pumpswas thatif the pump were made voir having a cover platen thereon and a to have suflfi cient'capacityto move the actuated shouldered bore 2% in the lower wall thereof. The

work members atlthenecessary rate oi speed, then 20 cover plate 22 may be secured to the reservoir til it wasdiffieuit to build upv ahigh enough pressure j witha gasket 2! therebetween, and there is prefin the hydrauliccircuitiwiththepurnp toperfonn I erably provided a breather passage 23 to permit thenecessary work, this limitation being duetoj the fluid level within the reservoir to change,

the factthat' when the pump displacement was t Receivable in the bore M is the shouldered body made large for thesakeofspeedit required great 25 26 of the pump proper. The body 26 is retained strengthto' exertenoumthrust onthejpumpingfl in position by aretaining or clamping ring 2% member to dejveiop a high unit pressure inflthe and a resilient sealing ring as at Bil prevents pumped fluid. I lj v fiuidjleakage from thereservoir around the said 'Theobject ofjthe presentin ntionisjtofpro-Y t n ofiy vide an improved typepump offlthe manually op "30C The upper en d of the body 2 6 1s bored as atfl? .erated typewhich iscapable divgeneratingajplu-f 1 and reciprocably receives a piston M" which is ediated Another objectflof thisinvep ion is the proby a compression spring 36. vision of a n ianually actuated hydraulicjpump The piston M is centrally axially bored as at dd which canselectively displace alargevolume o f 1 andthere isreciprocable therein a plunger dd fluid t low presj'ure and'a smaller volume of havin ro es o pa sa es e din he e o e fluidatahigherpressure. l asindicated atti'. The plunger Mi comprises a A still furtherbbject'isthe provision offs, hand stop collar or abutting means M which engages pump having a largefand asrria11.%piston whichjf theupper suriace of the'piston it whenthe said may be independently operable for. I displacing" plunger is moved downw d y i o h p p bodya It;will be notedthat the;piston 34 completely means All engages f the said piston. 'I'he plunger l llabove' the abutting means exlgstends 'throughjthe cover Hand has connected requires only a discharge a bell crank lever Mthatihcludes the elongated endlst rt cnw i it 1 The p'lungejr dlljbeldwthe Piston 34 is shouldered ive' engagement with the said duirectionof travel. The ense rid pistonl 'cylinder arrangertion 54 preferably is grooved and continuously urged upwardly to abut the ring dd ours ng grooves M p at the time the abutting M therewith Ta linkjflfi that is fastened to one arm of A I tendsinto an axial bore Ed carries a resilient sealing member 58 for the purvalve generally indicated at III, the inlet of which communicates by a passage 12 with a port 14 in the lower end of the bore 55, and whose outlet communicates directly with the discharge conduit ii.

In operation, the lever 48 is first moved to bring the pistons into their Figure 2 position. Thereafter a pumping stroke is accomplished by moving the lever 48 counterclockwise about its pivotal support on the plate 22. As the plunger 40 moves downwardly, the portion 54 thereof displaces fluid from the bore 56 through the passage I2 and check valve Iii to the discharge conduit i2. When the abutting means 44 on the plunger 40 engages the piston 34 and the said piston begins to move with the plunger 40, then fluid isalso displaced from the bore 32 through the check valve 59, passage 12, and check valve ill to the discharge conduit it.

On the return stroke of the piston and plunger, the plunger first moves upwardly sufliciently far to uncover the grooves 42. Thereafter, the plunger 40 and piston 34 move together with the fluid required to flll the cavities beneath the plunger and piston flowing thereto through the grooves 42 from the reservoir 20.

As long as the fluid circuit being supplied requires only low pressure, the lever 48 can be reciprocated between the limits necessary to actuate the piston 34. However, when the pressure requirements of the circuitv increase, then the resistance to movement oi the piston 34 increases and the pump operator will commence oscillating the lever 50 between its Figure 1 position and the position wherein the abutting means 44 strikes the top of the piston 34. When the lever is being so oscillated, only the portion 54 of the plunger is displacing fluid while the check valve 59 prevents the high pressure fluid from standing on the piston 34.

It will be noted that the pump has two rates ,of displacement, one when both the piston 34 and plunger 4|! are displacing fluid to the discharge conduit, and another when only the plunger 40 is displacing fluid. It will be apparent that the two rates of discharging fluid can be governed by the relative sizes of the said plunger and piston, and that a correspondingly higher pressure can be developed on the pumped fluid by the plunger 40 than by the piston 34 with the same exertion on the handle 50.

The arrangement shown in Figure 5 is similar to that shown in Figures 1 through 4 and is identifled by similar numerals with the addition of a subscript a.

The difference in'the construction of Figure 5 is principally that of relocating the discharge check valve 10a so that it is in axial alignment movable members in the check valves 59a and 10a are conically shaped valve members rather than balls, this diilerence being essentially one of design rather than function or of principle.

In Figure'5'there is also shown a sealing member II which is adapted for being engaged by the abutting means 44a when the plunger 40a is moved downwardly to pick up the piston 540. By the sealing member I, leakage of fluid from the cylinder 32a back to the reservoir is substantially prevented, while the resiliency of the said member absorbs the shock of the abutting means 44a when it meets the said piston.

It will be apparent that .his invention provides for a simple pumping structure which is easily manufactured and assembled and which has relatively few working parts. The pump is adapted for discharging fluid at a plurality of rates of flow and'at a plurality of pressures. The several rates of flow are obtained by a single operating lever by oscillating the same between different limits of travel.

It will be understood that this invention is susceptible to modification in order to adopt it to different usages and conditions and, accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

We claim:

1. In a pump; first and second pumping means having different displacements; a single actuating means for said pumping means selectively operable to actuate the smaller thereof independently or both thereof simultaneously; means of supplying fluid to be pumped to said pumping means; valve means permitting the flow of fluid from the larger of said pumping means to the smaller but not vice versa; and other valve means permitting the flow of fluid from the smaller of said pumping means to a discharge.

2. In a pump; a larger and a smaller pumping means; a single actuating means for said pumping means operable to actuate the smaller thereof independently or both thereof simultaneously; means of supplying fluid to be pumped to said pumping means; a check valve opening from the larger of said pumping means to the smaller; and another check valve opening from the smaller of said pumping means to a discharge.

3. In a pump; a pump body; a large .and a small fluid displacing means within said body; .a single actuating means for said pumping means mounted on said body and movable between first predetermined limits for actuating only the smaller of said pumping means; and between said second predetermined limits for actuating both of said pumping means simultaneously; a discharge port in said body; a" first check valve opening from said smaller pumping means to said discharge port; and a second check valve opening from the larger of said pumping means into the smaller.

4. In a pump; a flrst piston and cylinder; a second piston passing through said flrst piston and extending into a second cylinder; an actuating means connected with said second piston for reciprocating the same; abutment means on said actuating means for abutting and actuating said second piston during a predetermined portion of the movement of said actuating means; acheck valve opening from said first cylinder into said second; another check valve opening from said second cylinder to a discharge port and means of supplying fluid to be pumped to said cylinders.

5. In a pump; a, first piston and cylinder; a second piston extending through said first piston and into a second cylinder; abutment means liminto inoperative position; a secondcylinder: a

second piston in said second cylinder and extending through said first piston an actuating means for reciprocating said second piston; abutment means carried by said actuating means for engaging said first piston when the second thereof has moved a predetermined distance in its pumping direction; a flow passage extending from said first cylinder to the space above-said first piston and adapted for being interrupted when said first piston is engaged by said abutment means; and independent check valves between the discharge side of said pump and said cylinders.

'1. In a pump; a pump body having a discharge port; a first cylinder bore in said body; a first piston in said first bore; yielding means con-- tinuously urging said first piston toward a position of greatest volume of said bore; a second cylinder bore in said body: a second piston in said second bore; actuating means for said second piston extending through said first piston and adapted for engagement with said first piston in at least the pumping direction of movement of said second piston; a flow passage extending along said actuating means for connecting said first cylinder bore with the space above said first, piston and adapted for interruption when said abutment means engages said first piston; a check valve opening from said first cylinder bore into said second; and a second check valve opening from said second cylinder bore into said discharge port.

8. In a pump; telescoping piston means of different diameters; individual cylinder means for receiving said pistons; a check valve opening from the larger of said cylinders into the smaller, and another check valve opening from the smaller of said cylinders to a discharge; a flow passage extending along the telescoping parts of said pistons and adapted for being interrupted in response to the movement of the inner thereof a predetermined amount in its pumping direction; means operable thereafter to connect said pistons together for the simultaneous movement thereof; and an actuating means for said pistons comprising a pivoted lever connected with the said inner piston.

9. In a pump; first and second telescoping pistons; first and second cylinders within which said pistons are reciprocable; yielding means continuously urging the larger of said pistons in a direction opposite to its pumping direction; a single actuating means for reciprocating the smaller of said pistons independently between predetermined limits, or both of said pistons simultaneously between other predetermined limits; passage means for supplying fluid to be pumped to said cylinders extending through the larger of said pistons; a discharge passage for said first cylinder including a check valve opening from said first cylinder into the second thereof; and a discharge passage for said second cylinder comprising a check valve opening from said second cylinder to a discharge port.

WALTER. ERNST. WARREN R. TUCKER.

REFERENCES CITED The following references are of record in the file of'this patent:

UNITED s'ra'ms PATENTS 2,083,854 McGee June 15, 1937 

